testing -- Em.Application.extend

app.js

import Ember from 'ember';
import Resolver from 'ember/resolver';
import loadInitializers from 'ember/load-initializers';
import config from './config/environment';
import 'demo-app/helpers/equal';
var App;

Ember.MODEL_FACTORY_INJECTIONS = true;

App = Ember.Application.extend({
  modulePrefix: config.modulePrefix,
  podModulePrefix: config.podModulePrefix,
  Resolver: Resolver
});

loadInitializers(App, config.modulePrefix);

export default App;

application.controller.js

import Ember from 'ember';

export default Ember.Controller.extend({
  appName:'Ember Twiddle'
});

application.template.hbs

<h1>Welcome to {{appName}}</h1>
<br>
<br>
{{outlet}}
{{#if (equal '1' '1')}}
yes
{{/if}}
<br>
<br>

helpers.equal.js

Em.Helper.helper(function([value1, value2]) {
return value1 === value2;
});

twiddle.json

{
  "version": "0.4.14",
  "EmberENV": {
    "FEATURES": {}
  },
  "dependencies": {
    "jquery": "https://cdnjs.cloudflare.com/ajax/libs/jquery/1.11.3/jquery.js",
    "ember": "2.1.0",
    "ember-data": "https://cdnjs.cloudflare.com/ajax/libs/ember-data.js/2.1.0/ember-data.js",
    "ember-template-compiler": "2.1.0"
  }
}